Air inflated structure and control



y 1 w. w. BIRD 2,990,836

AIR INFLATED STRUCTURE AND CONTROL Filed Sept. 24, 1958 1 12$ 36 3e JZZ W --l||||||llll'- ml O JNVENTOR. MLTERI KB/RD BY. /5 4; I @M,M,MX@4Z;

32 ATTORNEYS.

2,990 836 AIR INFLATED STRUCTURE AND CONTROL Walter W. Bird, Williamsville, N.Y., assignor to Birdair Structures, Inc., Buffalo, N.Y. Filed Sept. 24, 1958, Ser. No. 762,989 4 Claims. (Cl. 135-1) This invention relates to air supported structures and more particularly to improved means for control of erection of air-inflated towers or the like.

A primary object of the invention is to provide an improved control arrangement in a self-erecting air-supported tower structure which is to be so tensioned throughout the erection process as to provide improved stabilization of the tower during the erection process and subsequent thereto. Other objects and advantages of the invention will appear from the specification hereinafter.

In the drawing:

FIG. 1 is an elevational view through a tower embodying the invention, illustrating the tower at various stages of erection thereof;

FIG. 2 is a vertical sectional view through a device of the invention showing it in fully retracted condition prior to final deflation for transport or storage;

FIG. 3 is a top plan view taken along line III-III of FIG. 1; and

FIG. 4 is a section taken along line IV-IV of FIG. 1.

Generally stated, the invention contemplates an improved arrangement for control of erection and retraction of a tower of the type adapted to be erected simply by inflation by means of moderate air or gas pressure, such as by a centrifugal blower or the like. As shown in the drawing the tower of the invention is constructed to comprise generally a base plate or ring :15 about which is secured the lower end portion of a cone or cylindrically shaped sleeve of fabric 20 comprising the wall structure of the tower when inflated. The bottom end of the wall structure 20 is conveniently fixed to the base ring 15 by any suitable manner. Or, in the alternative any other suitable means may be used to anchor the bottom of the tower to a support. The sleeve 20 is closed at its top end either by fabric or by a cap or platform member as illustrated for example at 22. The outside diameter of the plate 22 is less than the diameter of the adjacent portion of the sleeve 20, for reasons to be explained hereinafter.

A tensioning device is attached to the top plate 22 and as shown herein may conveniently comprise a cable 30 fixed at its lower end to a winch or the like as indicated at 32 and is preferably connected at its upper end to the three or more divergent strands 34 which tie at their outer ends to the top plate 22 so that tension forces through the cable 30 will not tend to tilt the top plate 22. As shown in he drawing, intermediately of its vertical extent the sleeve 20 is provided with any preferred number of transverse spanners such as are indicated generally at 35, 36, in FIG. 1. As illustrated the spanners may comprise skirts 37, 38 formed of fabric sewn or otherwise permanently fixed to the sleeve 20 at their peripheries and are provided at intervals therearound with radial cables 40 which are fixedly connected at theirother ends to central rings 42, 44, through which the cable threads. Or, in the alternative, the spanners may comprise suitably perforated fabric sheets having cable receiving openings at their centers; or any other suitable arrangement for transmitting radial pull upon the sleeve 20 to initiate infolding thereof. Whereas, the drawing herewith illustrates the device of the invention to include tWo intermediate spanners, it is to be understood that any preferred number thereof may be employed, according to the height of the tower and the indicated need.

The base plate 15 is anchored to the erection site by ted States Patent any convenient means; and a low pressure air blower as indicated at 50 or other air supply device such as a pump, gas cylinder or generator is arranged to deliver air or gas under pressure to the interior of the sleeve 20 for purposes to be explained hereinafter.

Thus, it will be appreciated that the tower fabrication as hereinabove described is fully flexible and well adapted when deflated to be folded for storage and transport purposes. The device of the invention is .designed for many purposes under a large variety of installation conditions, and may for example be carried on a transport vehicle with the base ring 15 permanently mounted thereon. Or, the unit may be designed for field erection purposes, and thus upon unloading of the unit at the erection site, the base ring 15 is first anchored to the ground and the air supply device 50 is then activated to commence inflation of the structure. As air moves into the structure the winch 32 controlling the cable 30 is initially braked to permit the air to first inflate the sleeve only into the condition shown in FIG. 2. Then, the winch is permitted to unwind in response to further tower inflating tensions transmitted to the cable 30, as by selective slipping of the clutch controlling the winch. Thus, the inflating air initially causes the tower structure to rise progressively through the positions shown in FIG. 1, while being constantly under restraint of the tension cable 30.

This mode of operation maintains the partially erected tower in stable condition and invulnerably to wind gusts or the like throughout the erection process. Throughout the entire erection process the erected portion of the tower structure is maintained under the centralizing tension effects of the cable 30, as explained hereinabove. If desired, external guy wire devices may of course be additionally employed. Subsequent deflation and controlled collapse and nesting of the structure into the transport or storage configuration thereof as shown in FIG. 2, is attained by simply permitting escape of the inflating air and reverse operation of the winch 32. As the cable 30 pulls the top plate 22 down the latter first infolds the top section of the tower until plate 22 moves down to the position shown at spanner 36, whereupon it bears against the spanner cables 34 and then proceeds to infold the intermediate section of the tower, and so on.

The tower of the invention may be employed for a variety of purposes, such as for support of military field equipment or the like. For example, a Searchlight or radar reflector device may be carried by the top plate 22. However, it will of course be understood that the tower may be used for any other purposes, and that the top plate 22 may for example mount an interiorly supported functional component in lieu of the exteriorly mounted apparatus as described. Or, the tower of the invention may be readily constructed to include an antenna device which may be in the form of a metallic screen or metal coated fabric or the like applied to the interior or to the exterior of the tower sleeve material, and comprising any desired vertical portion thereof, as may be preferred.

It is of course to be understood that although only one form of the invention has been illustrated and described in detail, it will be apparent to those skilled in the art that the invention is not so limited but that various changes may be made therein such as operating the cable 30 by any suitable means in lieu of the winch, without departing from the spirit of the invention or the scope of the appended claims.

I claim:

1. In a self-erecting air inflated tower structure comprising a base member, a vertically elongate sleeve formed of flexible substantially airtight material fixed at its bottom end to said base member and having a reduced diameter closure member at its upper end sealing the latter, interior spanning means disposed transversely of said sleeve member intermediately of its ends, a tension cable extending from said closure member and passing through said spanning means and being guided thereby to remain at the center thereof, whereby said tower may be progressively inflated and deflated by alternate input and release of air from the interior of said sleeve coincident with selective pulling upon said cable.

2. A self-erecting air inflated tower comprising a vertically elongate sleeve formed of flexible substantially airtight material adapted to be fixed at its bottom end to a base, said sleeve having a reduced diameter closure member at its upper and sealing the latter, tension cable means extending from said closure member, abutment means spanning the interior of said sleeve intermediately of its ends and slidably accommodating said cable means to guide the latter to remain at the approximate center of said sleeve, whereby said tower may be progressively inflated and deflated and correspondingly unfolded and infolded by alternate input and release of air from the interior of said sleeve coincident with selective control of said cable means.

3. In a self-erecting air inflated tower structure comprising a base member, a vertically elongate sleeve formed of relatively flexible substantially airtight material fixed at its bottom end to said base member and having a reduced diameter relatively rigid closure member at its upper end sealing the latter, interior spanning means disposed transversely of said sleeve member intermediately of its ends, a tension cable extending from said closure member and passing through the approximate center of said spanning means, whereby said tower may be progressively inflated and deflated by alternate input and release of air from the interior of said sleeve coincident with selective pulling upon said cable.

4. A self-erecting air inflated housing comprising an elongate casing formed of flexible substantially airtight material adapted to be fixed at one end to a support, said casing having a reduced size closure member at its opposite end sealing the latter, tension cable means extending from said closure member, infolding control means spanning the interior of said casing intermediately of its ends and slidably accommodating said cable means at the approximate center of said control means, whereby said housing may be progressively inflated and deflated and correspondingly unfolded and infolded by alternate input and release of air from the interior of said casing coincident with selective control of said cable means.

References Cited in the file of this patent UNITED STATES PATENTS 1,296,687 Nichols Mar. 11, 1919 1,553,340 Upson Sept. 15, 1925 2,693,195 Frieder et al. Nov. 2, 1954 2,731,055 Smith Jan. 17, 1956 2,849,011 Bird Aug. 26, 1958 

